U.S. patent application number 13/050817 was filed with the patent office on 2012-06-14 for gas-barrier heat-seal composite films and vacuum insulation panels comprising the same.
This patent application is currently assigned to INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE. Invention is credited to Jui-hung Hsu, Dan-Cheng Kong, Chang-Ming Wong.
Application Number | 20120148785 13/050817 |
Document ID | / |
Family ID | 46199660 |
Filed Date | 2012-06-14 |
United States Patent
Application |
20120148785 |
Kind Code |
A1 |
Hsu; Jui-hung ; et
al. |
June 14, 2012 |
GAS-BARRIER HEAT-SEAL COMPOSITE FILMS AND VACUUM INSULATION PANELS
COMPRISING THE SAME
Abstract
A gas-barrier heat-seal composite film is provided. The
gas-barrier heat-seal composite film includes a heat-seal layer
including very low density polyethylene (VLDPE), low density
polyethylene (LDPE), linear low density polyethylene (LLDPE), high
density polyethylene (HDPE), metallocene polyethylene (mPE),
metallocene linear low density polyethylene (mLLDPE), ethylene
vinyl acetate (EVA) copolymer, ethylene-propylene (EP) copolymer or
ethylene-propylene-butene (EPB) terpolymer, and a gas-barrier layer
formed on the heat-seal layer, wherein the gas-barrier layer
includes a plurality of composite layers, each including a polymer
substrate and a single layer or multiple layers of metal or oxide
thereof which is formed on one side or both sides of the polymer
substrate, and the polymer substrate includes uniaxial-stretched or
biaxial-stretched polyethylene terephthalate (PET), polybutylene
terephthalate (PBT), polyimide (PI), ethylene/vinyl alcohol (EVOH)
copolymer or a combination thereof. The invention also provides a
vacuum insulation panel including the composite film.
Inventors: |
Hsu; Jui-hung; (Changhua
City, TW) ; Kong; Dan-Cheng; (Hsinchu City, TW)
; Wong; Chang-Ming; (Chupei, TW) |
Assignee: |
INDUSTRIAL TECHNOLOGY RESEARCH
INSTITUTE
Hsinchu County
TW
|
Family ID: |
46199660 |
Appl. No.: |
13/050817 |
Filed: |
March 17, 2011 |
Current U.S.
Class: |
428/69 ; 428/334;
428/335; 428/336; 428/344; 428/349 |
Current CPC
Class: |
B32B 27/065 20130101;
B32B 2307/514 20130101; Y10T 428/265 20150115; B32B 2307/304
20130101; Y10T 428/263 20150115; B32B 2266/025 20130101; Y10T
428/25 20150115; B32B 2266/0228 20130101; B32B 15/20 20130101; Y10T
428/24 20150115; B32B 15/09 20130101; Y10T 428/264 20150115; Y10T
428/2826 20150115; B32B 27/327 20130101; Y10T 428/231 20150115;
B32B 2266/0214 20130101; B32B 2307/31 20130101; B32B 2255/06
20130101; B32B 15/08 20130101; B32B 27/36 20130101; B32B 2255/205
20130101; B32B 2266/06 20130101; B32B 2307/7242 20130101; Y10T
428/2804 20150115; B32B 27/306 20130101; B32B 2607/00 20130101;
B32B 27/32 20130101; B32B 5/18 20130101; B32B 2255/20 20130101 |
Class at
Publication: |
428/69 ; 428/349;
428/344; 428/334; 428/335; 428/336 |
International
Class: |
B32B 27/06 20060101
B32B027/06; B32B 7/12 20060101 B32B007/12; B32B 27/08 20060101
B32B027/08; B32B 15/08 20060101 B32B015/08; B32B 5/18 20060101
B32B005/18; B32B 27/32 20060101 B32B027/32; E04B 1/78 20060101
E04B001/78 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 2010 |
TW |
099142987 |
Claims
1. A gas-barrier heat-seal composite film, comprising: a heat-seal
layer comprising very low density polyethylene (VLDPE), low density
polyethylene (LDPE), linear low density polyethylene (LLDPE), high
density polyethylene (HDPE), metallocene polyethylene (mPE),
metallocene linear low density polyethylene (mLLDPE), ethylene
vinyl acetate (EVA) copolymer, ethylene-propylene (EP) copolymer or
ethylene-propylene-butene (EPB) terpolymer; and a gas-barrier layer
comprising a plurality of composite layers formed on one side of
the heat-seal layer, each of the composite layers comprising
multiple layers of metal or oxide thereof formed on one side or
both sides of a polymer substrate, wherein the polymer substrate
comprises uniaxial-stretched or biaxial-stretched polyethylene
terephthalate (PET), polybutylene terephthalate (PBT), polyimide
(PI), ethylene/vinyl alcohol (EVOH) copolymer or a combination
thereof.
2. The gas-barrier heat-seal composite film as claimed in claim 1,
wherein the layer of metal or oxide thereof comprises metal
elements in the third period or the fourth period or oxides
thereof.
3. The gas-barrier heat-seal composite film as claimed in claim 2,
wherein the layer of metal or oxide thereof comprises aluminum,
chromium, copper, titanium, zinc, aluminum oxide, calcium oxide,
titanium oxide or zinc oxide.
4. The gas-barrier heat-seal composite film as claimed in claim 1,
further comprising at least one primer layer formed between the
polymer substrate and the layer of metal or oxide thereof or
between the layers of metal or oxide thereof.
5. The gas-barrier heat-seal composite film as claimed in claim 4,
wherein the primer layer comprises urethane acrylate, epoxy
acrylate, silicone acrylate or a mixture thereof.
6. The gas-barrier heat-seal composite film as claimed in claim 1,
further comprising a protective layer formed on the gas-barrier
layer.
7. The gas-barrier heat-seal composite film as claimed in claim 6,
wherein the protective layer comprises uniaxial-stretched or
biaxial-stretched polyethylene terephthalate (PET), polyamide (PA),
poly(ethylene-2,6-naphthalate) (PEN) or polyimide (PI).
8. The gas-barrier heat-seal composite film as claimed in claim 6,
further comprising a glue formed between the heat-seal layer, the
gas-barrier layer and the protective layer and between the
composite layers of the gas-barrier layer.
9. The gas-barrier heat-seal composite film as claimed in claim 1,
wherein the heat-seal layer has a thickness of 12-100 .mu.m.
10. The gas-barrier heat-seal composite film as claimed in claim 1,
wherein the polymer substrate has a thickness of 12-50 .mu.m.
11. The gas-barrier heat-seal composite film as claimed in claim 1,
wherein the layer of metal or oxide thereof has a thickness of
30-100 nm.
12. The gas-barrier heat-seal composite film as claimed in claim 1,
wherein the protective layer has a thickness of 12-50 .mu.m.
13. A vacuum insulation panel, comprising: a foam material with a
density smaller than 0.1 g/cm.sup.3, the content of open-cells
greater than 90%, a bubble size smaller than 250 .mu.m and an
pressure resistance greater than 1 kg/cm.sup.2; and a gas-barrier
heat-seal composite film as claimed in claim 1, covering the foam
material, with an oxygen transmission rate less than 0.01
cc/m.sup.2dayatm and a water vapor transmission rate less than 0.01
cc/m.sup.2day.
14. The vacuum insulation panel as claimed in claim 13, wherein the
foam material comprises open-cell polystyrene or open-cell
polypropylene.
15. The vacuum insulation panel as claimed in claim 13, wherein the
foam material has a bubble size smaller than 100 .mu.m.
16. The vacuum insulation panel as claimed in claim 13, wherein the
vacuum insulation panel has a coefficient of thermal conductivity
lower than 0.01 W/mk.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims priority of Taiwan Patent
Application No. 99142987, filed on Dec. 9, 2010, the entirety of
which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a gas-barrier heat-seal material,
and in particular to a gas-barrier heat-seal composite film and a
vacuum insulation panel comprising the composite film.
[0004] 2. Description of the Related Art
[0005] A high-gas-barrier film material possesses a high gas
barrier and flexibility. When the high-gas-barrier film material is
utilized in a vacuum seal or a gas-barrier package, the effect of
not allowing gas to notably pass thereto can last for several
years. Among the commonly used gas-barrier film materials, plastic
film materials do not come close to meet gas barrier requirements.
Although glass materials have a high gas barrier, it cannot be
applied easily due to its shortcomings of having an
energy-consuming process, having no flexibility and having a heavy
weight etc. Metal film materials such as aluminum foil have the
shortcomings of having an energy-consuming process and
non-recyclability, and its high thermal conductivity makes it
inappropriate for application in certain specific products (for
example vacuum insulation panels). Since a single material cannot
meet the ideal characteristics, composite film materials (for
example plastic film materials with metal or silicon oxide
(SiO.sub.x) evaporated thereon) have been developed and can meet
flexibility and high gas barrier requirements simultaneously; in
spite, the gas barrier of the composite film materials can be
greatly improved.
BRIEF SUMMARY OF THE INVENTION
[0006] One embodiment of the invention provides a gas-barrier
heat-seal composite film comprising a heat-seal layer comprising
very low density polyethylene (VLDPE), low density polyethylene
(LDPE), linear low density polyethylene (LLDPE), high density
polyethylene (HDPE), metallocene polyethylene (mPE), metallocene
linear low density polyethylene (mLLDPE), ethylene vinyl acetate
(EVA) copolymer, ethylene-propylene (EP) copolymer or
ethylene-propylene-butene (EPB) terpolymer, and a gas-barrier layer
comprising a plurality of composite layers formed on the heat-seal
layer, each comprising a single layer or multiple layers of metal
or oxide formed on one side or both sides of a polymer substrate,
wherein the polymer substrate comprises uniaxial-stretched or
biaxial-stretched polyethylene terephthalate (PET), polybutylene
terephthalate (PBT), polyimide (PI), ethylene/vinyl alcohol (EVOH)
copolymer or a combination thereof.
[0007] The gas-barrier heat-seal composite film further comprises
at least one primer layer formed between the polymer substrate and
the layer of metal or oxide thereof or between the layers of metal
or oxide thereof. The primer layer comprises urethane acrylate,
epoxy acrylate, silicone acrylate or a mixture thereof. The
gas-barrier heat-seal composite film further comprises a protective
layer formed on the gas-barrier layer. The protective layer
comprises uniaxial-stretched or biaxial-stretched polyethylene
terephthalate (PET), polyamide (PA), poly(ethylene-2,6-naphthalate)
(PEN) or polyimide (PI).
[0008] The disclosed gas-barrier heat-seal composite film structure
comprises three parts, a protective layer, a high-gas-barrier
composite layer and a heat-seal layer in order. In the structure,
the protective layer provides printability and protects the
underlying high-gas-barrier composite layer from physical damage.
The high-gas-barrier composite layer provides a high gas barrier.
The heat-seal layer provides heat-sealability. The primer layer
conducted into the high-gas-barrier composite layer improves metal
adhesion and gas barrier effects.
[0009] The invention provides a gas-barrier heat-seal composite
film with flexibility, a high gas barrier, a light weight, energy
savings and recyclability which can replace the conventional
flexible aluminum foil high-gas-barrier films, and is appropriate
for application in high-gas-barrier food products and medicine
packaging materials and a vacuum insulation panel of a freezer, a
refrigerator, an icehouse and a building, as a carbon reduction
material, with an oxygen transmission rate smaller than 0.01
cc/m.sup.2dayatm, a water vapor transmission rate smaller than 0.01
g/m.sup.2day and a heat-seal strength greater than 1,500 g/25 mm.
Additionally, the process for the gas-barrier heat-seal composite
film saves energy and is simple, and is appropriate for application
in roll to roll production. The composite film also possesses
weatherability under a low temperature due to the glass transition
temperature, Tg, of the heat seal layer is lower than 0.degree.
C.
[0010] One embodiment of the invention provides a vacuum insulation
panel (VIP) comprising a foam material with a density smaller than
0.1 g/cm.sup.3, an open-cell ratio greater than 90%, a bubble size
smaller than 250 .mu.m and pressure resistance greater than 1
kg/cm.sup.2, and the disclosed gas-barrier heat-seal composite
film, covering the foam material, with an oxygen transmission rate
lower than 0.01 cc/m.sup.2dayatm and a water vapor transmission
rate lower than 0.01 cc/m.sup.2day.
[0011] A detailed description is given in the following embodiments
with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention can be more fully understood by reading the
subsequent detailed description and examples with references made
to the accompanying drawing, wherein:
[0013] FIG. 1 shows a gas-barrier heat-seal composite film
according to an embodiment of the invention;
[0014] FIG. 2 shows a gas-barrier heat-seal composite film
according to an embodiment of the invention;
[0015] FIG. 3 shows a gas-barrier heat-seal composite film
according to an embodiment of the invention; and
[0016] FIG. 4 shows an inner structure of an open-cell polystyrene
foam material according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] One embodiment of the invention provides a gas-barrier
heat-seal composite film comprising a heat-seal layer comprising
very low density polyethylene (VLDPE), low density polyethylene
(LDPE), linear low density polyethylene (LLDPE), high density
polyethylene (HDPE), metallocene polyethylene (mPE), metallocene
linear low density polyethylene (mLLDPE), ethylene vinyl acetate
(EVA) copolymer, ethylene-propylene (EP) copolymer or
ethylene-propylene-butene (EPB) terpolymer, and a gas-barrier layer
comprising a plurality of composite layers (at least two composite
layers) formed on the heat-seal layer, each comprising a single
layer or multiple layers of metal or oxide thereof formed on one
side or both sides of a polymer substrate, wherein the polymer
substrate comprises uniaxial-stretched or biaxial-stretched
polyethylene terephthalate (PET), polybutylene terephthalate (PBT),
polyimide (PI), ethylene/vinyl alcohol (EVOH) copolymer or a
combination thereof, for example polyethylene terephthalate (PET)
with an ethylene/vinyl alcohol (EVOH) copolymer skin.
[0018] The layer of metal or oxide thereof may comprise metal
elements in the third period or the fourth period or oxides
thereof, for example aluminum, chromium, copper, titanium, zinc,
aluminum oxide, calcium oxide, titanium oxide or zinc oxide. In an
embodiment, the single or multiple layers of metal or oxide thereof
are formed on one side or both sides of the polymer substrate by,
for example vacuum evaporation.
[0019] The gas-barrier heat-seal composite film further comprises
at least one primer layer formed between the polymer substrate and
the layer of metal or oxide thereof or between two layers of metal
or oxide thereof to improve metal adhesion and gas barrier effect.
The primer layer may comprise urethane acrylate, epoxy acrylate,
silicone acrylate or a mixture thereof.
[0020] The gas-barrier heat-seal composite film further comprises a
protective layer formed on the gas-barrier layer. The protective
layer may comprise uniaxial-stretched or biaxial-stretched
polyethylene terephthalate (PET), polyamide (PA),
poly(ethylene-2,6-naphthalate) (PEN) or polyimide (PI).
[0021] The gas-barrier heat-seal composite film further comprises a
glue formed between the heat-seal layer, the gas-barrier layer and
the protective layer and between the two composite layers of the
gas-barrier layer to bind the heat-seal layer, the gas-barrier
layer and the protective layer and the two composite layers of the
gas-barrier layer. The glue may comprise epoxy resin, polyurethane
resin, acrylic resin, cellulose resin or low density polyethylene
(LDPE).
[0022] The heat-seal layer has a thickness from 12 .mu.m to 100
.mu.m, preferably from 20 .mu.m to 60 .mu.m. The polymer substrate
for vacuum evaporation has a thickness of about 10-50 .mu.m,
preferably 12-25 .mu.m. The layer of metal or oxide thereof has a
thickness of 30-100 nm, preferably 40-80 nm. The protective layer
has a thickness of about 12-50 .mu.m, preferably 12-25 .mu.m.
[0023] The disclosed gas-barrier heat-seal composite film structure
comprises three parts, a protective layer, a high-gas-barrier
composite layer and a heat-seal layer in order. In the structure,
the protective layer provides printability and protects the
underlying high-gas-barrier composite layer from physical damage.
The high-gas-barrier composite layer provides a high gas-barrier.
The heat-seal layer provides heat-sealability. The primer layer
conducted into the high-gas-barrier composite layer improves metal
adhesion and gas barrier effects.
[0024] The invention provides a gas-barrier heat-seal composite
film with flexibility, a high gas barrier, a light weight, energy
savings and recyclability which can replace the conventional
flexible aluminum foil high-gas-barrier films, and is appropriate
for application in high-gas-barrier food products and medicine
packaging materials and a vacuum insulation panel of a freezer, a
refrigerator, an icehouse and a building, as a carbon reduction
material, with an oxygen transmission rate smaller than 0.01
cc/m.sup.2dayatm, a vapor transmission rate smaller than 0.01
g/m.sup.2day and a heat-seal strength greater than 1,500 g/25 mm.
Additionally, the process for the gas-barrier heat-seal composite
film saves energy and is simple, and is appropriate for application
in roll to roll production. The composite film also possesses
weatherability under a low temperature due to the glass transition
temperature, Tg, of the heat seal layer is lower than 0.degree.
C.
[0025] One embodiment of the invention provides a vacuum insulation
panel (VIP) comprising a foam material with a density smaller than
0.1 g/cm.sup.3, the content of open-cells greater than 90%, a
bubble size smaller than 250 .mu.m, preferably smaller than 100
.mu.m, and pressure resistance greater than 1 kg/cm.sup.2, and the
disclosed gas-barrier heat-seal composite film, covering the foam
material, with an oxygen transmission rate lower than 0.01
cc/m.sup.2dayatm and a vapor transmission rate lower than 0.01
cc/m.sup.2day.
[0026] The foam material may comprise open-cell polystyrene (PS) or
polypropylene (PP).
[0027] The vacuum insulation panel has a coefficient of thermal
conductivity lower than 0.01 W/mk.
Example 1
[0028] Preparation of the Gas-Barrier Heat-Seal Composite Film
(1)
[0029] A multiple-layered composite film was prepared by the
evaporation and binding method, as shown in FIG. 1. The composite
film comprised, from top to bottom, a PET protective layer 10 (with
a thickness of 13 .mu.m), an epoxy resin glue 12 (with a thickness
of 7 .mu.m), a PET composite layer 14 (a PET substrate 16 with a
thickness of 17 .mu.m vacuum-metallized with two aluminum layers 18
with a respective thickness of 30 nm on both sides thereof, and a
primer layer 20 with a thickness of 7 .mu.m), an epoxy resin glue
22 (with a thickness of 7 .mu.m), a PET composite layer 24 (a PET
substrate 26 with a thickness of 17 .mu.m plated with two aluminum
layers 28 with a respective thickness of 30 nm on both sides
thereof, and a primer layer 30 with a thickness of 7 .mu.m), an
epoxy resin glue 32 (with a thickness of 7 .mu.m) and a PE
heat-seal layer 34 (with a thickness of 60 .mu.m). In this example,
the oxygen transmission rate of the gas-barrier heat-seal composite
film was lower than 0.01 cc/m.sup.2dayAtm. The heat-seal strength
of the gas-barrier heat-seal composite film was greater than 1,500
g/25 mm.
Example 2
[0030] Preparation of the Gas-Barrier Heat-Seal Composite Film
(2)
[0031] A multiple-layered composite film was prepared by the
evaporation and binding method, as shown in FIG. 2. The composite
film comprised, from top to bottom, a PET composite layer 36 (a PET
substrate 38 with a thickness of 17 .mu.m vacuum-metallized with
two aluminum layers 40 with a respective thickness of 30 nm on one
side thereof toward an epoxy resin glue 44, and a primer layer 42
with a thickness of 7 .mu.m), the epoxy resin glue 44 (with a
thickness of 7 .mu.m), a PET composite layer 46 (a PET substrate 48
with a thickness of 17 .mu.m vacuum-metallized with two aluminum
layers 50 with a respective thickness of 30 nm on one side thereof
toward an epoxy resin glue 44, and a primer layer 52 with a
thickness of 7 .mu.m), an epoxy resin glue 54 (with a thickness of
7 .mu.m) and a EP-copolymer heat-seal layer 56 (with a thickness of
60 .mu.m). In this example, the oxygen transmission rate of the
gas-barrier heat-seal composite film was lower than 0.01
cc/m.sup.2dayAtm. The water vapor transmission rate of the
gas-barrier heat-seal composite film was lower than 0.01
cc/m.sup.2day. Additionally, the heat-seal strength of the
gas-barrier heat-seal composite film was greater than 1,500 g/25
mm.
Example 3
[0032] Preparation of the Gas-Barrier Heat-Seal Composite Film
(3)
[0033] A multiple-layered composite film was prepared by the
evaporation and binding method, as shown in FIG. 3. The composite
film comprised, from top to bottom, a PET protective layer 58 (with
a thickness of 13 .mu.m), an epoxy resin glue 60 (with a thickness
of 7 .mu.m), a PET composite layer 62 (a PET substrate 64 with a
thickness of 17 .mu.m vacuum-metallized with two aluminum layers 66
with a respective thickness of 30 nm on both sides thereof, and a
primer layer 68 with a thickness of 7 .mu.m), an epoxy resin glue
70 (with a thickness of 7 .mu.m), a EVOH composite layer 72 (a EVOH
substrate 74 containing 44% ethylene with a thickness of 20 .mu.m
metallized with one aluminum layer 76 with a thickness of 30 nm on
one side thereof toward the epoxy resin glue 70 bound with the
metallized aluminum layer 76), an epoxy resin glue 78 (with a
thickness of 7 .mu.m) and a PE heat-seal layer 80 (with a thickness
of 60 .mu.m). In this example, the oxygen transmission rate of the
gas-barrier heat-seal composite film was less than 0.01
cc/m.sup.2dayAtm. The heat-seal strength of the gas-barrier
heat-seal composite film was greater than 1,500 g/25 mm.
Example 4
[0034] Preparation of the Foam Material of the Vacuum Insulation
Panel
[0035] In this example, polystyrene (PS) with a molecular weight of
200,000 to 300,000 was utilized. First, PS was uniformly mixed with
other resins (for example low density polyethylene (LDPE)), fillers
(for example calcium carbonate and carbon black) and nucleating
agents (for example calcium stearate and zinc stearate) using an
extruder under 150-200.degree. C. to form PS resin particles. A
foam material was then prepared by a continuous method. In the
continuous method, two tandem-arranged extruders were connected.
The second extruder was connected to a mold head. PS resin
particles were conducted into the first extruder. In the first
extruder, PS resin was melted, a gas, for example, carbon dioxide
(CO.sub.2), was conducted thereto and then the gas and PS resin
were mixed under 180-220.degree. C. The melted PS resin mixed with
the gas was then cooled and delivered to the mold head through the
second extruder under 120-140.degree. C. When the melted PS resin
mixed with the gas passed through the mold head, the foam material
was formed. The inner structure of the open-cell PS foam material
is shown in FIG. 4. The pressure of the mold head was set to 800
psi-2,000 psi. In this example, the prepared foam material had a
density of 0.05-0.09 g/cm.sup.3, a bubble size of 80-250 .mu.m, the
content of open-cells greater than 95% and pressure resistance
greater than 1 kg/cm.sup.2.
Example 5
[0036] Preparation of the Vacuum Insulation Panel
[0037] After the PS resin was processed by the continuous method
and foamed by supercritical carbon dioxide (CO.sub.2), the
open-cell PS foam material was obtained (as prepared by Example 4).
The foam material was then packaged by the gas-barrier heat-seal
composite film (as prepared by Examples 1-3), vacuum-evacuated and
heat-sealed. The vacuum insulation panel was finally prepared.
Specifically, after evacuation, the pressure within the vacuum
insulation panel must be lower than 0.75 torr (1 mbar). In this
example, the prepared vacuum insulation panel had a coefficient of
thermal conductivity of 0.006-0.01 W/mk.
[0038] While the invention has been described by way of example and
in terms of preferred embodiment, it is to be understood that the
invention is not limited thereto. To the contrary, it is intended
to cover various modifications and similar arrangements (as would
be apparent to those skilled in the art). Therefore, the scope of
the appended claims should be accorded the broadest interpretation
so as to encompass all such modifications and similar
arrangements.
* * * * *